Controlling electric motors and apparatus therefor.



Patented lune I9, |900. y H. LEilLTNER: CDNTRDLLlM ELEGIRIG Mj'mRS. MmAP-P'ARATUS THEREFOB.-

(Application filed. July, 10 1899.4),

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No. 652,!24. Patented .lune I9, |900. H. LEITNER.

GONTROLLING ELECTRIC MOTORS AND APPARATUS THEREFOR.

(Application filed Juy 10, 1899.)

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No. 652,|24. Patented June I9., |900.

H. LEITNER.

GONTBLLING ELECTRIC IIOTDRS AND APPARATUSA THEREFOR.

(Application led July 10, 1899.)

(No Model.) 8 Sheets-Sheet 3.

No.^652,|24. Patented June I9, |900. H. LEITNER.

CONTRDLLING ELECTRIC MUTURS AND APPARATUS THEREFUR.

(Application filed July 10, 1899.)

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No. 652,|24. Patented lune I9, |900.

H. LEITNER. CONTROLLING ELECTRIC MOTORS AND APPARATUS THEREFOR.

(Application led July 10, 1899.)

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l/ Z7 W- n a a o o A s a M No. 652,|24. Patnted lune I9, |900. H.LEITNEB.

CNTRLLING ELECTRIC MOTORS AND APPARATUS THEREFOR.

(Application led Julyv 10, 1899.)

(No Model.) v l 6 Sheets-Sheet 5.

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UNITED STATES PATENT OFFICE.

HENRY IEITNER, OF LONDON, ENGLAND.

coNTRoLLlNG ELECTRIC MOTORS AND APPAFmTUs THEREFOR.

SPECIFICATION forming part of Letters Patent No. 652,124, dated J' une19, 1900.

Application filed July 10,1899.

To a w/tom, it may concern:

Be it known that I, HENRY LEITNER, electrical engineer, a citizen ofEngland, residing at 207 Piccadilly, London, England, have inventedcertain new and useful Improvements in Controlling Electric Motors andApparatus for that Purpose, (for which I have made application for apatent in Great Britain, dated May 4, 1899, No. 9,414,) of which thefollowing is a specification.

My invention relates to means of controlling electric motors,particularly such as are employed for propelling vehicles.

It comprises an arrangement of motors and generators and apparatus forvarying the connections between the motors andthe generators, as I shalldescribe by way of example, referring to the accompanying drawings.

Figure 1 is a diagram of the motors and generators. Fig. 2 shows thesurfaces of the two commutator-cylinders developed, with theirconducting-segments. Fig. 3 is a side View, partly sectional. Fig. 4 isan end view, and Fig. 5 is a plan, of the controlling-commutator. Figs.6 to 14, inclusive, are diagrams illustrating the different connectionseffected by the controller.

Referring to Fig. l, ct at are vthe armatures of two motors. l) bindicate their commutators, and c c the coils of their field-magnets.These two motors may be variously connected to a pair of batteries orgenerators cl d and a pair of exciting generators or batteries e e.Instead of two separate motors a single motor may be employed having twoindependent windings a and commutators l) on a single shaft, which canbe grouped in series or in parallel, as can the two separate motors. Themain battery or generator is in two parts d d, which can be placed inseries or parallel, and a second and smaller battery,which may con'-sist of four cells, is also divided into two parts e e. This smallbattery or exciter is for the field-magnets and is sufficiently strongto keep them powerfully excited independently of the main circuit. Theexciter e e is placed in the main circuit in opposition to the maingenerator d d, or it might be in an independent field-circuit. Besidesthe various voltages and speeds obtained by different groupings of thearmatures and main battery certain intermediate speeds are obtained bySerial No. 723,399. (No model.)

transferring the exciter to or from the main circuit. When e e is in themain circuit, it is in opposition to the electromotive force of the mainbattery, reducing its effective Voltage; but when e e is not in the maincircuit the full voltage of the main battery ol d is utilized. When theexciter e e is in 'circuit with the main battery d CZ, thearmature-current is supplied almost entirely through it, the resistanceof the field being much greater than that of the exciter, and the maincurrent acts so as to charge the exciter to its fullest extent, keepingits voltage up to the extreme limit, and thus highly exciting the field.The exciter also serves to choke off any sudden rush of current to thearmature on starting or increasing the voltage. rIhe exciter preventsany danger of reversal of the field, owing to the motor acting as agenerator, as may occur in the case of the motors of a vehicle when thevehicle descendsa gradient. Any current so generated serves to chargethe main battery. The controlling-commutator comprises two cylinders fg, each having bridging contacts, which are arranged so as to have nocross connections. The two cylinders are turned simultaneously by ahandle h and gearing fi, so as to bring narrow sets of bridges (one setfor each grou ping of motors and generators) against brushes 7c,connected to the terminals of the motors and generators.

As shown at Fig. 2, there are nine sets of bridge-contacts numbered fromI to IX in each group, the similarly-numbered sets in each group beingused together. The vertical dotted lines indicate the position of thebrushes, and the connections are indicated by numerals corresponding tothose marked on Fig. l, for the various terminals l 2 3 4 are thearmature-brushes, 5 and 6 the held-magnet terminals, 7 8 9 l0 are thepoles of the main battery, and l1,12,13,and 14 are the poles of theexciter. The positions I and II are for backward driving, with thepolarity of the field reversed. III is the stopping position, withelectric brake. IV to IX are the positions for forward driving, withprogressivelyincreased speed.

It will be observed that Figs. 6 to 14 are respectively marked withRoman numerals I to IX, designating the various positions of IOO thecontroller corresponding to the similarlynumbered contacts indicated inFig. 2, which in each of its horizontal lines shows allot' the contactsmade for each ease. Take, for instance, position I, (shown in Fig. 6,)it will be seen in Fig. 2, reading from the left, that 14 is connectedto 1, 3 to 2, 4 to 10, S to 9, 7 to 11, 13 to 12, 6 to 11, and 14 to 5,and by again referring to diagram I, Fig. 6, all these connections canbe thereon traced, and so on for the other positions.

In position I, as shown in Fig. 6, the connections are such that thearmatures d are in series, the divisions of both batteries d and e inseries, the field c is connected to exciter e, and one pole of exciter cis connected to the like pole of the main battery d, the other pole ofthe exciter e being connected to one of the armature-brushes. The maincurrent thus passes to the armature l) through exciter c in oppositionto its electromotive force.

In position II, as shown in Fig. 7, the only change is that the twoparts of the main battery d d are in parallel, the voltage, andconsequently the speed, being thus reduced.

In position III (see Fig. 8) the armatures Z) b are short-'circuited andthe field c is excited; but in the direction for forward driving themain batteries d d are cut out. In this case any motion of the motorwould set up a current in the armature which would resist furthermotion, and so act as a brake, tending to stop the motor. In position IV(see Fig. 9) the direction of driving is forward, but otherwise similarto II, with eld reversed, and position V (see Fig. 10) is similar to I,with field reversed. These give the two slowest` forward-driving speeds.

In position VI (see Fig. 11) both the armatures b h and the parts d elof the main battery are in series; but the exciter c c is cut out of themain circuit and forms an independent circuit with the field. Thebatterypole 7 is directly connected to brush 1.

In position VII (see Fig. 12) the armatures i b b are in parallel, whiledel remain in series, and the exciter c c is again introduced.

In position VIII (see Fig. 13) the connections are as in VI, but withthe armatures in i parallel, the exciter e e beingin an independi entcircuit.

In position IX (see Fig. 14) the connections l are as in VIII; but thetwo parts of the exciter c c are in parallel and the field is thereforeweakened, as the voltage of the exciter is not rsufficient to excite thefield 'fully except when all its cells are in series. This positiongives the highest attainable speed. As the full voltage of the maingenerator is utilized the armatures are in parallel and the field isreduced in strength.

In order that the cylinders f and g when they are turned by the handle hmay always take such a position that the brushes lt are on thecontact-pieces, one of the cylinders has on its axis a star-wheel j, theteeth of which are engaged by a spring-pawl Z, having a roller which,springing in between .two of the teeth of j,brin gs the cylinders torest in the proper position. Between the two cylinders are the brushes7c, which are hinged at their lower ends and are pressed against the twocylinders f g by the pneumatic cylinder m, which is iniiated through avalve a. Thus the brushes are pressed quite evenly on the cylinders, andseparate springs are not required. In order to retain thecontrollingcommntator in the position for stopping and to preventaccidental reversal, the handle h has a spring-rod o, `with a projectionp at its lower end, which engagesin a notch inside a saddle-piece q,which is concentric with the operating-spindle. To move the handle fromthis position, the button at the top of the rod 0 has to be presseddown.

An indicating-plate is provided, having on it the numbers I to IX, sothat the operator can see at a glance the position oi' thecontrolling-commutator.

Having thus described the nature of this invention and the best means Iknow ot' carrying the same into practical elect, I claim- 1. Forcontrolling electric motors, the combination of a main battery in4 twoparts, a

l smaller battery also made in two parts and having its poles inopposition to the main battery when connected thereto, a pair of motors,and a controlling-commutator adapted to eect various connections of thebatteries and motors, substantially as described.

2. A controllingcommutator comprising two cylinders geared together soas to be sim ultaneously revolved, these cylinders being provided withbridging-contacts having pairs of' brushes which are mounted between thecylinders pressed against them by an inflated pneumatic tube,substantially as described.

In testimony whereof I have hereunto set my hand in presence of twosubscribing witnesses.

HENRY LEITNER.

Witnesses:

A. M. GLASS, WALTER J. SKERTEN.

IOO

